Spinning arrangement

ABSTRACT

A spinning device is provided in which at least one sliver is opened to single fiber and the single fiber are deposited on a moveable collecting surface in the form of an air-permeable sieve belt. During transport on the collecting surface, the fiber veil is condensed transversely to its direction of movement to a fiber strand. The now roving-like fiber strand is transported through a nipping line and twisted to a thread by a twisting nozzle.

[0001] This application claims the priority of German application 101 01 660.3, filed Jan. 10, 2001, the disclosure of which is expressly incorporated by reference herein.

[0002] The present invention relates to a spinning arrangement comprising an opening roller for opening at least one sliver to single fibers, a driven, air-permeable collecting surface arranged directly adjacent to the opening roller and in the direction of motion of the single fibers for taking over the single fibers in the form of a wide fiber veil, a suction opening for condensing the fiber veil to a narrow fiber strand, said suction opening being covered by the collecting surface and tapering by means of two side edges in the direction of motion of the collecting surface from a starting width corresponding to the width of the fiber veil to a narrow suction slit, a nipping line provided at the end area of the suction opening for nipping the condensed fiber strand, and a twisting nozzle directly downstream of the nipping line for twisting the fiber strand to a thread.

[0003] A spinning arrangement of this type is prior art in U.S. Pat. No. 6,058,693. This spinning arrangement operates with a suctioned opening roller, whereby the purpose of the suction is to keep the surface speed of the opening roller low, so that the single fibers, while being combed from the at least one sliver, are not accelerated greatly. If this were not the case, there would be the risk that the end speed of the spun thread would increase endlessly, as the fiber material in the case of the known spinning device is sucessively accelerated during transport. The opening roller transfers the single fibers at a relatively low speed to a collecting surface in the form of an air-permeable suctioned transport roller; the suction opening arranged thereto tapers in the direction of motion of the collecting surface in such a way that the single fibers are laterally condensed and the original fiber veil is finally bundled to a roving-like fiber strand. Nowhere during this entire process is the fiber material bunched. The condensing process ends at the latest at the nipping line, and thereafter, in order to form a thread, the fiber strand is given its spinning twist by means of a twisting nozzle. A thread is produced which has a similar character to that known from so-called air jet spinning. The spun thread does not, therefore, have an absolutely pure open-end character.

[0004] The collecting surface is, as mentioned above, designed in the form of a transport roller, which may be arranged upstream of drafting roller. The transport roller must have a relatively large diameter, in order that the tapering of the suction area does not occur too spontaneously. This results in the design of the roller in very large dimensions.

[0005] It is an object of the present invention to simplify the design of the known spinning arrangement while retaining its general advantages, and to make it more adaptable in its geometry to local conditions.

[0006] This object has been achieved in accordance with the present invention in that the collecting surface is formed by an outer side of a circulating sieve belt.

[0007] As the sieve belt is flexible, it is more adaptable to the given parameters of a spinning arrangement than the known transport roller. In addition, the spinning arrangement can be designed overall in a signficantly compacter way.

[0008] In an embodiment of the invention it is provided that the collecting surface is formed by an essentially plane section of the sieve belt. Because the fiber veil is not deflected in the direction of motion of the collecting surface during the lateral bundling of its single fibers, the condensing of the fiber veil to a narrow fiber strand takes place with significantly more ease.

[0009] A suction housing comprising the suction opening is arranged advantageously at the collecting surface, the outer contour of said suction housing being adapted in the area of the collecting surface to the course of the sieve belt. Thus the sieve belt is guided properly, in particular also in its plane section. This is in particular then the case when the sieve belt is guided glidingly in the area of the collecting surface on the suction housing. The sieve belt can be driven in various ways. In an embodiment it is provided that the sieve belt is driven on its outer side by a nipping roller by means of friction. A nipping roller of this type is located on the above mentioned nipping line, that is at the end of the fiber veil condensed already to a narrow fiber strand, and presses on the one hand the single fibers against the sieve belt and on the other hand the sieve belt against the suction housing. In another embodiment the sieve belt is looped around a driving roller, which can either be arranged in the area of the nipping line or alternatively in the area of the opening roller. If as the driving roller is arranged in the area of the nipping line, a guiding roller can be arranged in the area of the opening roller to the driving roller.

[0010] In another embodiment of the invention, there is a certain distance, at the belt end facing away from the suction opening, between the sieve belt and the suction housing. In this area a cleaning device can be provided for the sieve belt, for example a cleaning roller or an airjet nozzle. A suction nozzle is also possible.

[0011] In order that the condensed fiber strand is not rolled out wide again, it is further provided that the suction opening extends to the area of the nipping line at that point where it graduates into a relatively narrow suction slit.

[0012] If as the sieve belt loops a driving roller, it can be provided that the nipping roller which effects the nipping line is disposed on the suction housing as well as on the driving roller. The advantage arises that the fiber strand need only be pressed at the nipping line with a slight pressure against the suction housing and that still the condensed fiber strand is blocked against twist at the nipping line. The actual transport only then takes place between the nipping roller and the driving roller.

[0013] The tapering of the suction opening can be designed as a V-shape. It is hereby advantageous when one side edge of the suction opening extends parallel to the direction of motion of the sieve belt. Thus only the other side edge extends transversely to the direction of motion of the sieve belt, so that the fiber veil is bundled to a narrow fiber strand only from one side edge. A type of gathering edge arises, on which the outer fibers of the fiber veil are somewhat rolled in. This gathering edge can be slightly raised in relation to the usual level of the suction housing, so that in the area of the gathering edge the gathering effect is particularly intensiv.

[0014] It is further advantageous when along the collecting surface, the suction housing comprises a plurality of sectioned chambers, all having varying levels of low pressure. At the beginning, a relatively high level of low pressure can be used in the area of the take over of the single fibers from the opening roller, while in most of the remaining areas of the suction opening a lower level of low pressure is possible. Only again in the area of the narrow suction slit at the end of the condensing zone should there be a higher level of low pressure present.

[0015] These and further objects, features and advantages of the present invention will become more readily apparent from the following detailed description thereof when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 is a partly sectional side view of a spinning arrangement according to the present invention;

[0017]FIG. 2 is a view in the direction of the arrow II of FIG. 1;

[0018]FIG. 3 is a view similar to FIG. 2 in a somewhat differently designed embodiment of the present invention; and

[0019]FIGS. 4,5 and 6 are further embodiments of the present invention in views similar to FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0020] The spinning arrangement according to FIGS. 1 and 2 comprises a feeding device 1, to which at least one sliver 2 is fed in feed direction A. The feeding device 1 is arranged directly upstream of an opening device 3, which opens the at least one sliver 2 to single fibers 4. The single fibers 4 are subsequently transfered to a collecting surface 6 of a sieve belt 5, which circulates in direction of motion B. The open single fibers 4 are taken up on the collecting surface 6 in the form of a wide fiber veil 7 and laterally condensed to a fiber strand 9 in a way to be described below.

[0021] The condensed fiber strand 9 is lightly pressed at a nipping line 8 by means of a nipping roller 10 onto the collecting surface 6. Directly downstream thereof, a twisting nozzle 11 is arranged, in which the twist of the thread 12 to be spun is generated. The thread 12 is withdrawn in withdrawal direction C by a delivery roller pair 13.

[0022] The feeding device 1 comprises a feed roller 14, which is driven in rotational direction D. A feed table 15 is arranged to the feed roller 14, said feed table 15 being hinged around a swivel axle 16 and being pressed against the feed roller 14 by the pressure of loading spring 17. A feed funnel 18 is arranged to the feed roller 14, which feed funnel 18 advantageously comprises a plurality of feed channels in the case of a plurality of slivers 2 being fed hereto. Alternatively, a broad band sliver of fiber material is also possible.

[0023] The opening device 3 comprises an opening roller 19, which is driven in the same rotational direction E as the feed roller 14. The periphery of the opening roller 19 comprises a toothed combing structure 20, the front of teeth having an advantageous negative angle.

[0024] The opening roller 19 has an effective width which corresponds to the width of the fed sliver 2 or slivers 2.

[0025] In the inside of the opening roller 19, a suction device 21 is located, which is connected to a vacuum source (not shown). By means of a perforation located on the periphery of the opening roller 19, suction is generated against the sliver 2 to be opened, which sucks the sliver 2 deep into the toothed combing structure 20, even when the opening roller 19 is driven at a relatively low speed of for example 2500 rpm. The suctioned area 22 extends over an angle of 45° to 90°, that is, as far as the single fibers 4 are to be transported on the periphery of the opening roller 19.

[0026] The sieve belt 5 is driven in moving direction B. Its effective width corresponds to the width of the transferred fiber veil 7. The sieve belt 5 is provided with a perforation, which permits suction from the outside inwards. The suction area 23 of the sieve belt 5 begins approximately there where the suction area 22 of the opening roller 19 ends. The suction opening 24 belonging to the suction area 23 comprises side edges 25 and 26, which are denoted in FIG. 2 by dotted lines, whereby it can be seen that the suction area 23 tapers in the direction of motion B of the collecting surface 6. The side edges 25 and 26 of the suction opening 24 thus form means for condensing the single fibers 4 transversely to their direction of motion to a roving-like fiber strand 9.

[0027] The nipping roller 10 comprises a base body, which is provided on its periphery with a flexible coating. The axle of the nipping roller 10 is swivel-mounted (not shown), so that the nipping roller 10 can be pressed lightly against the collecting surface 6. The nipping roller 10 is driven und drives in turn the sieve belt 5 on its outer side by means of friction.

[0028] The nipping roller 10 defines, together with the sieve belt 5, a nipping line 8 for the condensed fiber strand 9. The suction area 23 condenses to a fiber strand 9 the initially spread out fiber veil 7 transversely to its direction of motion, in conditions similar to be found in a classical drafting unit, so that the fiber strand 9 can, in this form, enter the twisting nozzle 11 in a way known in so-called air jet spinning. The fiber strand 9 is thus condensed to a thread 12.

[0029] The delivery roller pair 13 arranged downstream of the twisting nozzle 11 delivers the spun thread 12 in delivery direction C to a winding device (not shown), where the thread 12 is wound to a cross package. The geometrical arrangement of the spinning device is such that the collecting surface 6 of the sieve belt 5 is so closely adjacent to the periphery of the opening roller 19 that the single fibers 4 can be easily transfered at the end of the suction area 22 in the form of a fiber veil 7 to the collecting surface 6. The circumferential speed of the sieve belt 5 is somewhat greater than the speed of the in-coming single fibers 4.

[0030] The effective width of the opening roller 19 and the effective width of the sieve belt 5 is so chosen that either a very wide sliver 2, or a plurality of normal slivers 2, or a broad band sliver can be fed. It is advantageously provided that the fiber veil 7 comprises in its width a number of single fibers 4 which approximately corresponds to the number of fibers present in the cross section of the thread 12.

[0031] The sieve belt 5 should be of sufficiently length so that the tapering of the suction area 23 does not have to occur too spontaneously.

[0032] Thanks to its perforation, the peripheral speed of the opening roller 19 is less than those opening rollers used in open-end rotor spinning. As the end of the sliver 2, the so-called fiber beard, is pulled deep into the toothed combing structure 20, an intensive combing takes place. Because of the negative front angle of the combining teeth, the single fibers 4 at the end of the suction area 22 are transferred very quickly to the collecting surface 6, as a negative front angle strives to convey the transported single fibers 4 outwards.

[0033] The peripheral speed of the sieve belt 5 is, as mentioned above, somewhat greater than the speed of the single fibers 4 accelerated by the opening roller 19. The peripheral speed of the delivery roller pair 13 is in turn greater than the peripheral speed of the sieve belt 5. This means that the single fibers 4 are constantly accelerated somewhat during the entire spinning process, which is advantageous for their parallel position.

[0034] The fiber veil 7 deposited on the collecting surface 6 is initially quite wide; on the sieve belt 5 however, it is successively narrowed and thus to a large extent condensed, so that it can enter the twisting nozzle 11 easily.

[0035] The side edges 25 and 26 of the suction opening 24 extend in a V-shape towards one another in such a way that both side edges 25,26 form an acute angle in direction of motion B of the collecting surface 6.

[0036] The starting width of the suction opening 24 defines the effective width of the sieve belt 5 and the collecting surface 6 and corresponds initially to the width of the fiber veil 7 taken up from the opening roller 19. The end area of the suction opening 24 is just a relatively narrow suction slit 27, which is adapted to the fiber strand 9 to be condensed.

[0037] The collecting surface 6 is formed by the outer side of the sieve belt 5 and extends essentially plane where the sieve belt 5 is guided over the suction opening 24. The sieve belt 5 is guided in a sliding manner on a suction housing 28; there can, however, be a very slight distance between the sieve belt 5 and the suction housing 28. The outer contour 29 of the suction housing 28 defines hereby the plane section of the sieve belt 5.

[0038] As can be seen from FIG. 1 the sieve belt 5 with its idle belt end is raised from the suction housing 28 on the side of the suction housing 28 facing away from the suction opening 24 and is guided in this area by a tension element 32. A certain distance 31 then arises between the suction housing 28 and the belt end 30.

[0039] As can be further seen, the nipping line 8 is formed by a nipping roller 10 which presses the fiber strand 9 against the suction housing 28, said nipping roller 10 being driven in rotational direction K. The suction opening 24 extends, as can be seen, to the nipping line 8.

[0040] The suction housing 28 may extend along a plurality of spinning stations and is connected to a vacuum source (not shown) via a conduit 38.

[0041] In the following embodiments described below, the same reference numbers as above are used, insofar as the same components are involved. A repeat description of these same components is therefore omitted.

[0042] The embodiment according to FIG. 3 corresponds to a large extent to that shown in FIG. 2, the difference being that now a somewhat differently designed suction opening 34 is provided, of which a side edge 33 extends parallel to the direction of motion B of the sieve belt 5. The other side edge 35 of the suction opening 34 approaches the side edge 33 gradually, until only a narrow suction slit 27 is present. The transversely extending side edge 35, referred to as a ,,gathering edge“, solely effects the condensing process.

[0043] As can be seen in the variation according to FIG. 3, the nipping roller 36, which otherwise corresponds to the nipping roller 10 according to FIG. 1, is placed on the lateral edge of the sieve belt 5.

[0044] It can be provided that the gathering edge 35 lies somewhat higher on the suction housing 37 than the rest of the outer contour of the suction housing 37.

[0045] The variation according to FIG. 4 differs from the embodiment described above in FIGS. 1 and 2 essentially in that at the nipping line 8 a nipping roller 39 is now provided, which does not serve the drive of the sieve belt 5, but rather functions only as a twist block, so that the twist imparted by the twisting nozzle 11 does not retroact to the area of the fiber veil 7.

[0046] A driving roller 40 serves the drive of the sieve belt 5, which driving roller 40 is located in the area of the opening roller 19 and which is driven in rotational direction F. In contrast, in the area of the nipping line 8, the sieve belt 5 is laid over a deflecting guide of the suction housing 28. The driving roller 40 is located thus not on the outside, bur rather on the inside of the sieve belt 5.

[0047] The distance 41 between the idle belt end 30 and the suction housing 28 can be seen in FIG. 4. In this area, a tension roller 43 is arranged, as is a cleaning device 42 in the form of air jet acting on the sieve belt 5 from the outside.

[0048] Also in the embodiment according to FIG. 5, the sieve belt 5 is driven by a separate driving roller 44, which rotates in rotational direction G and over which the sieve belt 5 is looped. The driving roller 44 is located in the vicinity of the nipping line 8. The nipping roller 39 which forms the nipping line 8 acts here also in this variation only as a twist block.

[0049] In the area of the opening roller 19, the sieve belt 5 loops around a separate deflecting roller 45, which here is in the form of a preferably electronically adjustable tension roller. Again there is a distance 48 between the suction housing 28 and the idle belt end 30 of the sieve belt 5; in the area of the distance 48, a cleaning device 46, driven in rotational direction H, is provided in the form of a brush roller. The brush roller rotates, as can be seen from FIG. 5, in the opposite direction to the belt end of the sieve belt 5.

[0050] A cover 47 is provided for over the fiber veil 7, which cover 47 covers the entire fiber veil 7 without coming into contact therewith.

[0051] The embodiment according to FIG. 6 is in part similar to that of FIG. 5, that is, the collecting surface 6 comprising the sieve belt 5 is again driven in the area of the nipping line 8 by a driving roller 58, and is, in the area of the opening roller 19, guided via a deflecting roller 59. The idle belt end 30 of the sieve belt 5 is held tensioned by means of a tension roller 51. Here again, a distance 52 occurs between the here somewhat differently designed suction housing 54 and the belt end 30, in the area of said distance 52 a cleaning device 53 is provided. This cleaning device 53 in the form of an air jet is located this time inside the circulating sieve belt 5.

[0052] As is the case in the other above embodiments, the suction housing 54 comprises here three suction chambers 55, 56 and 57, which have their own vacuum source. The entire suction housing 54 can be adjusted in its position relevant to the sieve belt 5.

[0053] The suction chamber 55 provided in the area of the opening roller 19 is provided with a relatively strong low pressure, so that the fiber veil 7 taken over from the opening roller 19 reaches the sieve belt 5 reliably. The adjoining suction chamber 56, which takes up the most space, has a significantly lower level of low pressure, as here the gradually condensing fiber veil 7 need only to be transported. At the end area of the suction opening 24, a suction chamber 57 with a higher level of low pressure is again provided, as here a mostly condensed fiber strand 9 is present.

[0054] A further special feature of the embodiment according to FIG. 6 is a nipping roller 60, which defines the nipping line 8, and which has a relatively large diameter. This nipping roller 60 is disposed not only on the nipping line 8 at the suction housing 54, but also at the same time is disposed on a further nipping line 61 at the driving roller 58. The first nipping line 8 defines the end of the condensing zone, while the second nipping line 61 acts as a twist block. The enlarged diameter has the advantage that the flexible coating of the roller heats up less than in the case of a smaller roller.

[0055] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof. 

What is claimed is:
 1. A spinning arrangement comprising: an opening roller for opening at least one sliver to single fibers; a driven, air-permeable collecting surface arranged directly adjacent to the opening roller and in a direction of motion of the single fibers for taking over the single fibers in the form of a wide fiber veil; a suction opening for condensing the fiber veil to a narrow fiber strand, said suction opening being covered by the collecting surface and tapering by two side edges in a direction of motion of the collecting surface from a starting width corresponding to a width of the fiber veil to a narrow suction slit; a nipping line provided at an end area of the suction opening for nipping the condensed fiber strand; and a twisting nozzle directly downstream of the nipping line for twisting the fiber strand to a thread, wherein the collecting surface is formed by an outer side of a circulating sieve belt.
 2. A spinning arrangement according to claim 1, wherein the collecting surface is formed by an essentially plane section of the sieve belt.
 3. A spinning arrangement according to claim 2, wherein a suction housing comprising the suction opening is arranged at the collecting surface, the outer contour of the suction housing being adapted in the area of the collecting surface to the course of the sieve belt.
 4. A spinning arrangement according to claim 3, wherein the sieve belt is glidingly guided on the suction housing in the area of the collecting surface.
 5. A spinning arrangement according to claim 2, wherein the sieve belt is driven on its outer side by friction by a nipping roller.
 6. A spinning arrangement according to claim 1, wherein the sieve belt loops around a driving roller which is arranged in an area of the nipping line.
 7. A spinning arrangement according to claim 2, wherein the sieve belt loops around a driving roller which is arranged in an area of the nipping line.
 8. A spinning arrangement according to claim 1, wherein the sieve belt loops around a driving roller which is arranged in an area of the opening roller.
 9. A spinning arrangement according to claim 2, wherein the sieve belt loops around a driving roller which is arranged in an area of the opening roller.
 10. A spinning arrangement according to claim 6, wherein an idle roller is arranged for the sieve belt in an area of the opening roller.
 11. A spinning arrangement according to claim 7, wherein an idle roller is arranged for the sieve belt in an area of the opening roller.
 12. A spinning arrangement according to claim 1, wherein there is a spacing between the suction housing and a belt section travel path of the sieve belt which faces away from the suction opening.
 13. A spinning arrangement according to claim 2, wherein there is a spacing between the suction housing and a belt section travel path of the sieve belt which faces away from the suction opening.
 14. A spinning arrangement according to claim 3, wherein there is a spacing between the suction housing and a belt section travel path of the sieve belt which faces away from the suction opening.
 15. A spinning arrangement according to claim 5, wherein there is a spacing between the suction housing and a belt section travel path of the sieve belt which faces away from the suction opening.
 16. A spinning arrangement according to claim 6, wherein there is a spacing between the suction housing and a belt section travel path of the sieve belt which faces away from the suction opening.
 17. A spinning arrangement according to claim 12, wherein, in the area of the spacing, a cleaning device for the sieve belt is provided.
 18. A spinning arrangement according to claim 13, wherein, in the area of the spacing, a cleaning device for the sieve belt is provided.
 19. A spinning arrangement according to claim 14, wherein, in the area of the spacing, a cleaning device for the sieve belt is provided.
 20. A spinning arrangement according to claim 15, wherein, in the area of the spacing, a cleaning device for the sieve belt is provided.
 21. A spinning arrangement according to claim 1, wherein the nipping line is formed by a nipping roller which presses the fiber strand against the suction housing.
 22. A spinning arrangement according to claim 2, wherein the nipping line is formed by a nipping roller which presses the fiber strand against the suction housing.
 23. A spinning arrangement according to claim 6, wherein the nipping line is formed by a nipping roller which presses the fiber strand against the suction housing.
 24. A spinning arrangement according to claim 21, wherein the suction opening extends to the area of the nipping line.
 25. A spinning arrangement according to claim 23, wherein the suction opening extends to the area of the nipping line.
 26. A spinning arrangement according to claim 23, wherein the nipping roller is also disposed on the driving roller.
 27. A spinning arrangement according to claim 25, wherein the nipping roller is also disposed on the driving roller.
 28. A spinning arrangement according to claim 1, wherein one side edge of the suction opening extends parallel to the direction of motion of the sieve belt.
 29. A spinning arrangement according to claim 2, wherein one side edge of the suction opening extends parallel to the direction of motion of the sieve belt.
 30. A spinning arrangement according to claim 28, wherein the side edge is disposed continuously on the sieve belt.
 31. A spinning arrangement according to claim 3, wherein, along the collecting surface, the suction housing comprises a plurality of chambers with differing levels of pressure.
 32. A spinning arrangement according to claim 4, wherein, along the collecting surface, the suction housing comprises a plurality of chambers with differing levels of pressure.
 33. A spinning arrangement according to claim 5, wherein, along the collecting surface, the suction housing comprises a plurality of chambers with differing levels of pressure.
 34. A spinning arrangement according to claim 6, wherein, along the collecting surface, the suction housing comprises a plurality of chambers with differing levels of pressure.
 35. A spinning arrangement according to claim 8, wherein, along the collecting surface, the suction housing comprises a plurality of chambers with differing levels of pressure. 